<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>菜鸟教程(runoob.com)</title>
</head>

<body>

    <p>点击按钮，显示确认框。</p>
    <button onclick="myFunction()">点我</button>
    <p id="demo"></p>
    <script>
        function myFunction() {
            var x;
            var r = confirm("按下按钮!");
            if (r == true) {
                x = "你按下了\"确定\"按钮!";
            }
            else {
                x = "你按下了\"取消\"按钮!";
            }
            document.getElementById("demo").innerHTML = x;
        }
    </script>

</body>

</html>